Electrolyte-Gated Flexible MoS₂ Synaptic Transistors With Short-Term Plasticity

Simulation of biological synaptic function by electronic devices based on two-dimensional (2D) semiconductors is an emerging research. However, large-scale integration of synaptic devices particularly on flexible substrate are challenging. Electrolyte-gated 2D thin film transistors with low temperature processability for large-scale production have great potential in mimicing synaptic functions. Here, the molybdenum disulfide (MoS $_{{2}}{)}$ thin film transistors were transferred to ultrathin polymethyl methacrylate (PMMA) substrates integrally via one-step transfer method. Lithium perchlorate (LiClO $_{{4}}{)}$ electrolyte-gated MoS2 thin film transistors show superior flexible device performance with bending radius as low as 5 mm and synaptic pulse-dependent experiments demonstrate representative short-term plasticity. To further investigate the mechanism of synaptic plasticity, theoretical fit gives the model to disclose synaptic behavior. The experimental results are matched well with the proposed model and elucidate the effect of mechanical flexibility on synaptic performance. The excellent synaptic performance of the LiClO4 electrolyte-gated thin film transistors develop the application of 2D semiconductor devices in artificial synapses.